No, not sit-ups—a trainer recommends these four exercises if you want to strengthen your core

Man in a living room setting standing on one foot with the other knee raised to hip height like a standing march. there's a grey sofa to the side of him and windows behind. .

Many great core exercises—like crunches, sit-ups and heel taps—are performed lying on your back.

But if you prefer not to lie on the floor, or an injury prevents you from doing so, there are still ways to strengthen your core effectively.